The project encompasses medical ecology, zoogeography, evolution, the evaluation and discovery of new techniques, and the systematics of fleas, and is primarily based upon collections made during studies on vectors and reservoirs of rickettsial and viral infections undertaken in New Guinea, Pakistan, Ethiopia and other areas. As in the past, data on faunal studies on ectoparasites and their hosts will be used in investigations on the medical ecology of scrub typhus, tick typhus, plague and other infections, since data on faunal affinities have proven highly useful in predicting in which areas and habitats such infections may be endemic, even though their presence may have been completely unsuspected. The distribution (geographic and ecological) of fleas and their hosts will also continue to be studied from the zoogeographic point of view, especially since the research to date indicates that the data on fleas support the theory of Continental Drift, despite the opposition expressed to this hypothesis by nearly all mammalogists. Specially prepared photomicrographs will continue to be used in this program. During the next year it is planned to continue studies primarily on the family Pygiopsyllidae, the dominant representative of the Order in the Australian Region, but with elements present in Asia, Africa and South America as well. All the known genera will be fully illustrated and in most cases will be exemplified by a new species. Diagnosis and a key to the subfamilies, tribes and genera will be provided. Other new taxa from various parts of the world will be described, as feasible.